U.S. patent application number 15/061668 was filed with the patent office on 2016-09-08 for monopole antenna.
This patent application is currently assigned to Arcadyan Technology Corporation. The applicant listed for this patent is Arcadyan Technology Corporation. Invention is credited to Chih-Yung HUANG, Kuo-Chang LO, Min-Chi WU.
Application Number | 20160261051 15/061668 |
Document ID | / |
Family ID | 55451127 |
Filed Date | 2016-09-08 |
United States Patent
Application |
20160261051 |
Kind Code |
A1 |
WU; Min-Chi ; et
al. |
September 8, 2016 |
MONOPOLE ANTENNA
Abstract
A monopole antenna including a ground plane and a radiation body
is provided. The radiation body includes a feeding connection part,
a first radiation part, a second radiation part and a third
radiation part. The feeding connection part is adjacent to the
ground plane. The first radiation part connects one side of the
feeding connection part and extends along a first direction. The
first radiation part includes a metal patch whose width reduces
towards the first direction. The second radiation part, being
closer to the ground plane than the first radiation part, connects
the side of the feeding connection part and extends along the first
direction. The third radiation part connects the other side of the
feeding connection part and extends along a second direction
inverse to the first direction.
Inventors: |
WU; Min-Chi; (Zhubei City,
TW) ; LO; Kuo-Chang; (Miaoli County, TW) ;
HUANG; Chih-Yung; (Taichung City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Arcadyan Technology Corporation |
Hsinchu City |
|
TW |
|
|
Assignee: |
Arcadyan Technology
Corporation
Hsinchu City
TW
|
Family ID: |
55451127 |
Appl. No.: |
15/061668 |
Filed: |
March 4, 2016 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01Q 9/42 20130101; H01Q
1/38 20130101; H01Q 5/10 20150115; H01Q 1/243 20130101; H01Q 21/30
20130101; H01Q 5/371 20150115 |
International
Class: |
H01Q 21/30 20060101
H01Q021/30; H01Q 1/38 20060101 H01Q001/38; H01Q 5/10 20060101
H01Q005/10 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 5, 2015 |
TW |
104107004 |
Claims
1. A monopole antenna, which is printed on a substrate and
comprises: a ground plane; and a radiation body, comprising: a
feeding connection part adjacent to the ground plane; a first
radiation part connecting one side of the feeding connection part
and extending along a first direction, wherein the first radiation
part is in charge of a first operating frequency of the monopole
antenna and comprises: a metal patch whose width reduces towards
the first direction; a second radiation part connecting the side of
the feeding connection part and extending along the first
direction, wherein the second radiation part is closer to the
ground plane than the first radiation part and is in charge of a
second operating frequency of the monopole antenna; and a third
radiation part connecting the other side of the feeding connection
part and extending along a second direction inverse to the first
direction, wherein the third radiation part is in charge of a third
operating frequency of the monopole antenna, the second operating
frequency is higher than the third operating frequency, and the
third operating frequency is higher than the first operating
frequency.
2. The monopole antenna according to claim 1, wherein the feeding
connection part, the first radiation part and the third radiation
part form a T shape, the first radiation part and the third
radiation part are perpendicular to one end of the feeding
connection part farther away from the ground plane, and the first
radiation part and the third radiation part are inversely disposed
by 180.degree..
3. The monopole antenna according to claim 1, wherein the width of
the metal patch gradually reduces towards the first direction in a
smooth manner.
4. The monopole antenna according to claim 1, wherein the width of
the metal patch gradually reduces towards the first direction in a
stepped manner.
5. The monopole antenna according to claim 1, wherein the length of
the metal patch is larger than that of the second radiation
part.
6. The monopole antenna according to claim 1, wherein the metal
patch is adjacent to the side of the feeding connection part but
farther away from the terminal end of the first radiation part
extending towards the first direction.
7. The monopole antenna according to claim 1, wherein the width of
the second radiation part increases towards the first
direction.
8. The monopole antenna according to claim 1, wherein a signal
feeding region extending towards the second direction is disposed
at one end of the feeding connection part adjacent to the ground
plane for receiving RF signals.
9. The monopole antenna according to claim 1, wherein the radiation
body and the ground plane are disposed on the same side surface of
the substrate.
10. The monopole antenna according to claim 1, wherein the
radiation body and the ground plane are disposed on two sides
surfaces of the substrate respectively.
Description
[0001] This application claims the benefit of Taiwan application
Serial No. 104107004, filed Mar. 5, 2015, the disclosure of which
is incorporated by reference herein in its entirety.
TECHNICAL FIELD
[0002] The disclosure relates in general to an antenna, and more
particularly to a multi-band monopole antenna.
BACKGROUND
[0003] Along with the development in the communication technology,
wireless communication devices, such as notebook computers, mobile
phones, and wireless access points (AP), normally are capable of
operating in different bands. In response to the requirements of
performing wireless data transmission in different bands,
conventionally radio frequency (RF) front-end elements of the
device are implemented by broad-band antennas or multi-band
antennas.
[0004] However, the conventional design of multi-band antenna is
hard to be adapted to different operating bands, and is restricted
to low frequency bands.
[0005] Therefore, how to provide an adaptable multi-band antenna
having excellent antenna properties has become a prominent task for
the industries.
SUMMARY
[0006] The disclosure is directed to a multi-band monopole
antenna.
[0007] According to one embodiment of the present invention, a
monopole antenna is provided. The monopole antenna is printed on a
substrate and includes a ground plane and a radiation body. The
radiation body includes a feeding connection part, a first
radiation part, a second radiation part and a third radiation part.
The feeding connection part is adjacent to the ground plane. The
first radiation part, which connects one side of the feeding
connection part and extends along a first direction, is in charge
of a first operating frequency of the monopole antenna. The first
radiation part includes a metal patch whose width reduces towards
the first direction. The second radiation part, which connects the
side of the feeding connection part and extends along the first
direction, is closer to the ground plane than the first radiation
part and is in charge of a second operating frequency of the
monopole antenna. The third radiation part, which connects the
other side of the feeding connection part and extends along a
second direction inverse to the first direction, is in charge of a
third operating frequency of the monopole antenna. The second
operating frequency is higher than the third operating frequency,
and the third operating frequency is higher than the first
operating frequency.
[0008] The above and other aspects of the invention will become
better understood with regard to the following detailed description
of the preferred but non-limiting embodiment(s). The following
description is made with reference to the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a schematic diagram of a monopole antenna
according to an embodiment of the present invention.
[0010] FIG. 2A is a schematic diagram of a current path of a
radiation body under a first radiation frequency according to an
embodiment of the present invention.
[0011] FIG. 2B is a schematic diagram of a current path of a
radiation body under a second radiation frequency according to an
embodiment of the present invention.
[0012] FIG. 2C is a schematic diagram of a current path of a
radiation body under a third radiation frequency according to an
embodiment of the present invention.
[0013] FIG. 3A is a schematic diagram of a radiation unit according
to another embodiment of the present invention.
[0014] FIG. 3B is a schematic diagram of a radiation unit according
to an alternate embodiment of the present invention.
[0015] FIG. 4A is a schematic diagram of a radiation unit according
to an alternate of the present invention.
[0016] FIG. 4B is a schematic diagram of a radiation unit according
to an alternate of the present invention.
[0017] FIG. 5A is a side view of a monopole antenna according to an
embodiment of the present invention.
[0018] FIG. 5B is a side view of a monopole antenna according to
another embodiment of the present invention.
[0019] FIG. 6 is a measurement chart of reflection coefficient of a
monopole antenna according to an embodiment of the present
invention.
[0020] FIG. 7 is a simulation chart of radiation efficiency of a
monopole antenna according to an embodiment of the present
invention.
[0021] In the following detailed description, for purposes of
explanation, numerous specific details are set forth in order to
provide a thorough understanding of the disclosed embodiments. It
will be apparent, however, that one or more embodiments may be
practiced without these specific details. In other instances,
well-known structures and devices are schematically shown in order
to simplify the drawing.
DETAILED DESCRIPTION
[0022] A number of embodiments are disclosed below for elaborating
the invention. However, the embodiments of the invention are for
detailed descriptions only, not for limiting the scope of
protection of the present disclosure. Furthermore, secondary or
unimportant elements are omitted in the accompanying diagrams of
the embodiments for highlighting the technical features of the
present disclosure.
[0023] Referring to FIG. 1, a schematic diagram of a monopole
antenna 100 according to an embodiment of the present invention is
shown. As indicated in FIG. 1, the monopole antenna 100 includes a
ground plane 102 and a radiation body 104. The monopole antenna 100
is printed on a substrate. The radiation body 104 and the ground
plane 102 can be disposed on the same side surface or two side
surfaces of the substrate. In general, to avoid the properties of
the monopole antenna 100 being jeopardized, no other metal patterns
or elements are disposed within the substrate region on which the
projection of the radiation body 104 falls.
[0024] The radiation body 104 includes a feeding connection part
106, a first radiation part 108, a second radiation part 110 and a
third radiation part 112. The feeding connection part 106 is
adjacent to the ground plane 102, but is not directly connected to
the ground plane 102. In an embodiment, one end of the feeding
connection part 106 adjacent to the ground plane 102 includes a
signal feeding region 116 extending towards the direction D2 for
receiving RF signals. For example, a cable CB of 50 ohms can be
soldered at a feed point FP of the signal feeding region 116 such
that the RF signals can be directly fed to the monopole antenna 100
through the cable. For example, the cable is soldered at a top
right corner of the signal feeding region 116. However, the present
invention is not limited to the said exemplification. The monopole
antenna 100 can receive RF signals through a transmission line
printed on the substrate or through other generally known signal
transmission elements. In the present embodiment, by disposing the
signal feeding region 116 extending towards the direction D2 on the
feeding connection part 106, the impedance matching of the monopole
antenna 100 is effectively improved.
[0025] The first radiation part 108 connects a first side of the
feeding connection part 106 and extends along the direction D1
(towards the bottom of FIG. 1). The first radiation part 108 is
mainly in charge of a first operating frequency of the monopole
antenna 100. In an embodiment, of the many operating frequencies
excited by the monopole antenna 100, the first operating frequency
is relatively lower. By adjusting the length of the first radiation
part 108, the position of the first operating frequency can be
correspondingly adjusted. In general, the length from the feed
point FP to the terminal end of the first radiation part 108 is
approximately equivalent to 1/4 wavelength of the first operating
frequency.
[0026] In an embodiment, the overall antenna size can be reduced
through the bending design of the first radiation part 108. As
indicated in FIG. 1, the terminal end of the first radiation part
108 is bent upwards towards the ground plane 102 (direction D2). It
is understood that the first radiation part 108 can have other
bending design to increase the overall current path and reduce the
overall antenna size.
[0027] The first radiation part 108 includes a metal patch 114. The
length by which the metal patch 114 extends towards the direction
D1 is smaller than the length by which the first radiation part 108
extends towards the direction D1. The metal patch 114 is adjacent
to the first side of the feeding connection part 106 but farther
away from the terminal end of the first radiation part 108
extending towards the direction D1. As indicated in FIG. 1, the
width of the metal patch 114 reduces towards the direction D1, and
the length of the metal patch 114 is larger than that of the second
radiation part 110. Through the above disposition, the current path
towards the first radiation part 108 can be increased, and the
operating band of the antenna can be increased accordingly. The
metal patch 114 can also be used to adjust the impedance matching
of the monopole antenna 100, such that the monopole antenna 100 has
lower return loss.
[0028] The second radiation part 110 connects the first side of the
feeding connection part 106 and is closer to the ground plane 102
than the first radiation part 108. That is, the second radiation
part 110 and the first radiation part 108 both connect to the same
side of the feeding connection part 106. The second radiation part
110, which extends along the direction D1, is in charge of a second
operating frequency of the monopole antenna 100. In an embodiment,
of the many operating frequencies excited by the monopole antenna
100, the second operating frequency is relatively higher. By
adjusting the length of the second radiation part 110, the position
of the second operating frequency can be correspondingly adjusted.
In general, the length from the feed point FP to the terminal end
of the second radiation part 110 is approximately equivalent to 1/4
wavelength of the second operating frequency.
[0029] In an embodiment, the width of the second radiation part 110
increases towards the direction D1. As indicated in FIG. 1, the
width of the second radiation part 110 at the front end (the
junction with the feeding connection part 106) is smaller than that
at the middle end or at the terminal end. In the present
embodiment, the width increase of the second radiation part 110
towards the direction D1 not only effectively increases the
bandwidth of the second operating frequency of the monopole antenna
100 but further compensates the capacitance and inductance effects
of the second radiation part 110 with respect to the ground plane
102 and improves the impedance matching of the antenna.
[0030] The third radiation part 112 connects a second side of the
feeding connection part 106. The second side and the first side are
disposed oppositely. That is, the side of the feeding connection
part 106 on which the third radiation part 112 is disposed is
different from the side of the feeding connection part 106 on which
the first radiation part 108 and the second radiation part 110 are
disposed. As indicated in FIG. 1, the third radiation part 112
extends along a direction D2 inverse to the direction D1. In an
embodiment, the first radiation part 108 and the third radiation
part 112 connect the feeding connection part 106 by the other end
of the feeding connection part 106 farther away from the ground
plane 102, such that the feeding connection part 106, the first
radiation part 108 and the third radiation part 112 form a T shape.
The first radiation part 108 and the third radiation part 112 are
perpendicular to the feeding connection part 106. The first
radiation part 108 and the third radiation part 112 are inversely
disposed by 180.degree..
[0031] The third radiation part 112 is in charge of a third
operating frequency of the monopole antenna 100. In an embodiment,
of the many operating frequencies excited by the monopole antenna
100, the third operating frequency is relatively medium. By
adjusting the length of the third radiation part 112, the position
of the second operating frequency can be correspondingly adjusted.
In general, the length from the feed point FP to the terminal end
of the third radiation part 112 is approximately equivalent to 1/4
wavelength of the third operating frequency.
[0032] In an embodiment, the overall antenna size can be reduced
through the bending design of the third radiation part 112. As
indicated in FIG. 1, the terminal end of the third radiation part
112 is bent upwards towards the ground plane 102 (direction D2). It
is understood that the third radiation part 112 can have other
bending design to increase the overall current path and reduce the
overall antenna size.
[0033] Refer to FIGS. 2A, 2B, 2C. FIG. 2A is a schematic diagram of
a current path R1 of a radiation body DL 104 under a first
radiation frequency according to an embodiment of the present
invention. FIG. 2B is a schematic diagram of a current path R2 of a
radiation body 104 under a second radiation frequency according to
an embodiment of the present invention. FIG. 2C is a schematic
diagram of a current path R3 of a radiation body 104 under a third
radiation frequency according to an embodiment of the present
invention.
[0034] As disclosed above, since the first radiation part 108
mainly excites the radiation mode of the monopole antenna 100 under
the first operating frequency, the length of the current path R1
from the feed point FP to the terminal end of the first radiation
part 108 is approximately equivalent to 1/4 wavelength of the first
operating frequency. Similarly, since the second radiation part 110
mainly excites the radiation mode of the monopole antenna 100 under
the second operating frequency, the length of the current path R2
from the feed point FP to the terminal end of the second radiation
part 110 is approximately equivalent to 1/4 wavelength of the
second operating frequency. Similarly, since the third radiation
part 112 mainly excites the radiation mode of the monopole antenna
100 under the third operating frequency, the length of the current
path R3 from the feed point FP to the terminal end of the third
radiation part 112 is approximately equivalent to 1/4 wavelength of
the third operating frequency. In the present embodiment, the
second operating frequency is higher than the third operating
frequency, and the third operating frequency is higher than the
first operating frequency. Therefore, the current path R1 has the
largest length, the current path R3 comes second, and the current
path R2 has the smallest length.
[0035] FIG. 3A is a schematic diagram of a radiation unit 304
according to another embodiment of the present invention. The
radiation unit 304 is different from the radiation unit 104 of FIG.
1 mainly in that the width of the metal patch 314 of the first
radiation part 308 reduces towards the direction D1 in N steps,
wherein N is a positive integer greater than 2. As indicated in
FIG. 3A, the width of the metal patch 314 reduces towards the
direction D1 in 4 steps. As indicated in FIG. 1, the width of the
metal patch 114 reduces towards the direction D1 in 2 steps.
However, the present invention is not limited to the above
exemplifications. Any designs allowing the width of the metal patch
of the first radiation part of the radiation unit to gradually
reduce towards the direction D1 in a stepped manner are within the
spirit of the present invention.
[0036] FIG. 3B is a schematic diagram of a radiation unit 304'
according to an alternate embodiment of the present invention. The
radiation unit 304' of FIG. 3B is different from the radiation unit
104 of FIG. 1 mainly in that the width of the metal patch 304' of
the first radiation part 308' gradually reduces towards the
direction D1 in a smooth manner. As indicated in FIG. 3B, one side
of the metal patch 304' is a smooth curve having a radian. In
another embodiment, one side of the metal patch 304' can be a
slanted straight line.
[0037] FIG. 4A is a schematic diagram of a radiation unit 404
according to an alternate of the present invention. The radiation
unit 404 of FIG. 4A is different from the radiation unit 104 of
FIG. 1 mainly in that the width of the second radiation part 410
increases towards the direction D1 in M steps, wherein M is a
positive integer greater than 1. As indicated in FIG. 4A, the width
of the second radiation part 410 increases towards the direction D1
in 3 steps. The width of the second radiation part 110 of FIG. 1
increases towards the direction D1 in 2 steps. However, the present
invention is not limited to the above exemplifications. Any designs
allowing the width of the second radiation part of the radiation
unit to gradually increase towards the direction D1 in a stepped
manner are within the spirit of the present invention.
[0038] FIG. 4B is a schematic diagram of a radiation unit 404'
according to an alternate of the present invention. The radiation
unit 404' of FIG. 4B is different from the radiation unit 104 of
FIG. 1 mainly in that the width of the second radiation part 410
increases towards the direction D1 in a smooth manner. As indicated
in FIG. 4B, one side of the second radiation part 410 is a slanted
straight line. In another embodiment, one side of the second
radiation part 410 is a smooth curve having a radian.
[0039] It can be understood that the monopole antenna generated by
integrating and modifying the above embodiments is also within the
spirit of the present invention. For example, the metal patch 114
of the monopole antenna 100 can be replaced by the metal patch 314
of FIG. 3A or the metal patch 314' of FIG. 3B, and the second
radiation part 110 can be replaced by the second radiation part 410
of FIG. 4A or the second radiation part 410' of FIG. 4B.
[0040] Refer to FIG. 5A and FIG. 5B. FIG. 5A is a side view of a
monopole antenna according to an embodiment of the present
invention. FIG. 5B is a side view of a monopole antenna according
to another embodiment of the present invention.
[0041] The monopole antenna disclosed in above embodiments of the
present invention is printed on a substrate, and the radiation body
and the ground plane can be disposed on the same side surface or
two side surfaces of the substrate. FIG. 5A illustrate a
double-layer structure, wherein the radiation body of the monopole
antenna is printed on the metal layer M1, and the dielectric layer
DL is disposed under the metal layer M1. FIG. 5B is a triple-layer
structure, wherein the radiation body of the monopole antenna is
printed on the metal layer M1, the ground plane is printed on the
metal layer M2, and the dielectric layer DL is interposed between
the metal layer M1 and the metal layer M2. As disposed above, when
the monopole antenna is formed of a triple-layer structure, no
metal pattern will be printed and no elements will be disposed
within the substrate region on which the projection of the
radiation body falls.
[0042] FIG. 6 is a measurement chart of reflection coefficient
(S11) of a monopole antenna according to an embodiment of the
present invention. As indicated in FIG. 6, the reflection
coefficient is under -5 dB when the band is within the range of 724
MHz-960 MHz; the reflection coefficient is under -14 dB when the
band is within the range of 1.17 GHz-2.17 GHz; the reflection
coefficient is under -12 dB when the band is within the range of
2.17 GHz-2.7 GHz.
[0043] FIG. 7 is a simulation chart of radiation efficiency of a
monopole antenna according to an embodiment of the present
invention. As indicated in FIG. 7, the monopole antenna of the
present invention has three operating bands, and each operating
band produces excellent radiation efficiency.
[0044] To summarize, the monopole antenna disclosed in above
embodiments of the present invention not only has independent band
adjusting mechanisms, but also provides excellent impedance
matching and operating bandwidth. Furthermore, the monopole antenna
of the present invention can be independently operated on printed
circuit board or operated in collaboration with the system, and can
be conveniently used in different systems.
[0045] It will be apparent to those skilled in the art that various
modifications and variations can be made to the disclosed
embodiments. It is intended that the specification and examples be
considered as exemplary only, with a true scope of the disclosure
being indicated by the following claims and their equivalents.
* * * * *